In the prior art, hydraulic presses are used in roll-forming machines for forming apertures, or cutting workpieces. A hydraulic press includes a hydraulic drive which forces a first surface downwardly towards a die. Punches or dies are forced downwardly into the workpiece by the first surface. When such presses are used with a moving workpiece, a sliding surface on the die is engaged by the first surface. The sliding surface moves with a moving coil of material as it is forced downwardly, and slides relative to the first surface of the hydraulic drive as it moves. Since the hydraulic drive is applying a very large force to that sliding surface, the sliding surface contact creates an undue amount of friction and noise. Further, since movement of the workpiece alone pulls a sliding workpiece, it is sometimes difficult to achieve sufficient force to pull the sliding surface against the large downward force.
In the parent application of the present applications, an invention is disclosed wherein the hydraulic press moves with the die. In this way, the frictional contact between the downwardly moving surface and the die is eliminated. Instead, the die and the downward moving surface move together. This invention is an improvement over the prior art. However, since the moving coil of material must pull the press portions, it is sometimes difficult for a lower weight material to overcome the inertia of the relatively heavy press and die.
Thus, it is an object of this invention to disclose a hydraulic press and die which may be utilized with lighter materials.